/Engine/Source/Runtime/Json/Public/Dom/JsonObject.h
Try to get the field named FieldName as an array, or return false if it's another type
bool TryGetArrayField ( const [FString](API\Runtime\Core\Containers\FString) & FieldName, const [TArray](API\Runtime\Core\Containers\TArray)< [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FJsonValue](API\Runtime\Json\Dom\FJsonValue) > > *& OutArray ) const